Diamides of terephthalic acid



r 2,971,021 Ice Patented Feb. 7, 1951.

dro'carbon radicalsbeing attachedto the nitrogen atoms 2,971,027 aby'carbon nitrogen bonds. The benzene nucleus, DIAMIDES F TEREPHTHALICACID 7 Q Bruce W. Hottn,:0rinda,-Calif.-; assigndr'td California in theabbve formula m t,

p .t y contain alkyl radicals. In the fis gg g gggfi i San Fmflsmcorpolatter case (substitution by alkyl radicals), the sub V k V,stituents may contain up to 8 carbon atoms, all of which No Drawings:Original application Ang, f"3 0, 1 95 6',Sel'Q- may be in onesubstituent (e.g., a methyl, ethyl, hexyl or Qandthlyappllcatlollwsepli"23ft 10 octyl substituent) orwhichimay bedistributed among two ormor'e substituents(e.g., two'methyl, propylorbutyl" 4 Cl im ,(cfllzfiLsgj, substituents,"ora methyl and a butylsubstituent).

' As greasetthickening agents;'it is preferred to use" i a Hthediami'des of terephthalic acid having the type formula: ThlSmventionrelatesto"nw "compositionstiof matter' r315 useful as thickeningagents'fo fllibricatin "oil' com osi'-" tions. More particularly, th sin'v entidnfis directegto' 'Q' diamides or terephthalicacids whichareuseful td thicken lubricating oils; in which Ri and R3 each 'containsnot less than 6 carbon This application is a division ofHotten"application"" If t 2 are y Wei/Preferably Serial No;606,993,fi1e;1AUgUQfBO, 19'551; contain a totalof at leas't 24carbonatomsr If R and R It isprevailing practice to usesalts' ofcertainfatty acids are" aromatic radicals, )"P y contain total of orothersuitable acids and certairfimetals to produce high at 1555514carbon m -Y melting point'greases". Thusisodium and lithium stearates,Examblslof 1; i, a' i arthe normal hexyl,

alsosodiumand lithium salts of certainmohoamides'of' y y y undecyl, ytetradecyl,

polycarboxylic acids" are employed as 'greasetliickeners yoctadwlleicosyli and Y fadicalsibfanched to produce high melting pointgreases. Metal salt thickenchain isomers of "these same radicals;phenyl, biphenyl',

ers are disadvantageous, however, because the "metals flp t 'y -i y andP); nitrophenyli therein promote oxidation. b

Although nonmetal-containing grease thickening agents quinone, such as-froml anthraquinone; and radicals such-- have been proposed heretofore,most of these do notproas duce grease compositionshaying-highdroppingpoints (ASTM Method D-56 6 42) M @eoimr-Q It is ari"'object ofthe present inyentiomto provide newcompositions ofmattertusefuliin-the'preparation of l i grease compositions having highdroppingtpoints 'Q' Q It is* a particular object of this-inventiomtqprovide nonmetallic reasethickenin a ents usefulin-the re aration--ofgrea se composition: hiwingadroppingg-p oin zs inf the neighborhoodof400F. or"more',-preferably"500 F. 40

or more. I g

Another ob ect of this invention is to provide noyel CNHMNECOQQCONHCHHM.compounds which can be prepared economically WhlCh are nonmetallic innature and which are useful, among I other things, as grease thickeners.

These and other objects of the invention will be ap: parent from theensuing description and the appended 4 Specific examples of thickenersare as follows:

claims. NH-CO In accordance=with"the present-"invention, I havediscovered new compositionsmfimatter of the formulas v r g CllH31'NH'CO- CO NH-" B: a.

it C12Hi-NH CO- too-NH R, o R". t a

wherein R and R are selected rreinthe roup consisting a t t o H -NH-CO--CO-NH- -NH-00 of hydrocarbon and subshtutedhydrocarbon radicals at- 37A tached to the nitrogen atoms by carbon-nitrogen bonds, and wherein Rand R aresel'ected' from the group consisting1 i of hydrogen,hydrocarbonand su bstituted" hyand-'nitrotolyl radicals; radicalsderived from' anthra--- drocarbon radicals,such-hydrocarbonorsubstitutedhy: As grease thickening agents, the new compositioniofflsodium and lithium stearates, to produce lubricating.

greases. Thus, hydrocarbon and nonhydrocarbon oils may be used. Thehydrocarbon oils may be natural oils derived from petroleum, ,or theymay be synthetic oils produced by polymerization of olefins or bysynthesis from coal, carbon monoxide, etc. The nonhydrocarbon oils maybe of various types, e.g., silicates, silicones, esters, etc. Specificexamples of suitable base oils are as follows:

Naphthenic base, parafiinic base, and mixed base petroleum lubricatingoils; other hydrocarbon lubricants, e.g., lubricating oils derived fromcoal products, and synthetic oils, e.g., alkylene polymers (such aspolymers of propylene, butylene, etc., and mixtures thereof). Also,alkylene oxide-type polymers, dicarboxylic acid esters, liquid esters'of acids of phosphorus, alkyl aromatic hydrocarbons, polymers ofsilicon, etc. Synthetic oils of the alkylene oxide-type polymers may beused, e.g., propylene oxide polymers produced by polymerizingpropylene'oxide in the presence of water or alcohols, e.g., ethylalcohol;

esters of ethylene oxide-type polymers, e.g., acetylated propylene oxidepolymers prepared by acetylating propylene oxide polymers containinghydroxyl groups; polyethers prepared from alkylene glycols, e.g.,ethylene glycol, etc.

-The polymeric products prepared from the various alkylene oxides andalkylene glycols may be polyoxyalkylene diols or polyalkylene glycoderivatives; that is, the terminal hydroxy group can remain as such, orone orboth of the terminal hydroxy groups can be removed during thepolymerization reaction by esterification or etherification.

Synthetic oils of the dicarboxylicacid ester type include those whichare prepared by esterifying such dicarboxylic acids as adipic acid,azelaic acid, suberic acid, sebacic acid, alkenyl succinic acid, fumaricacid, maleic acid, etc., with alcohols such as butyl alcohol, hexylalcohol, 2-ethylhexyl alcohol, dodecyl alcohol, etc. Examples of dibasic(dicarboxylic) acid ester synthetic oils' include dibutyl adipate,dihexyl adipate, di-2-ethylhexyl sebacate, di-nhexylfumaric polymer.

Synthetic oils of the alkyl aromatic type include those which areprepared by alkylating benzene (e.g., dodecylbenzene, tetradecylbenzene,didodecylbenzene, etc.).

Synthetic oils of the type of polymers of silicon include the liquidesters of silicon and the polysiloxanes. The liquid esters of siliconand the polysiloxanes include those exemplified by tetraethyl silicate,tetraisopropyl silicate, tetra(4-methyl-2-butyl) silicate,tetra(4-methyl-2-penta) silicate, tetra(l-methoxy-2-propyl) silicate,poly-(methylsiloxane), poly(methylphenyl) siloxane, andpoly-(siloxyglycols), etc. a

The above base oils may be used individually as such, or in variouscombinations, wherever miscible or whereever made so by the use ofmutual solvents.

As grease thickening agents, the diamides of terephth'alic acid of thepresent invention may be incorporated in suitable base oils in varyingamounts. Where a high dropping point is not important, amounts as low as5% or less may be employed, but where high dropping points (i.e., about500 F. or higher) are desired, larger amounts of thickener should beemployed, for example, or higher, all such percentages being by weight,based on the finished grease. It is preferred to use no more than 30%.All percentages are by weight based on finished product.

Such greases may include other ingredients, such as oxidation and/orcorrosion inhibitors, etc.

The following specific examples will serve to illustrate the preparationof diamides of terephthalic acid of the present invention and theirusefulness as grease thickening PREPARATION OF TEREPHTI-LALDIAMIDESExample I .N-dodecyl-N-phenylterephthaldiamiae Terephthaloyl dichloride,

ciao-@0001 was prepared by refluxing an excess (90 ml.) of thionylchloride (SOCI with 83 grams of terephthalic acid in l-liter of toluenefor threehours, using 10 ml. of triethylamine as catalyst. The thionylchloride was added dropduring ten minutes. Alamine 21 is the trademarkof General Mills, Inc., Minneapolis, Minnesota, for a commercial fattyamine which is predominantly n-dodecylamine. The triethylamine was addedto function as a hydrogen chloride acceptor. The toluene was evaporatedoff on a steam plate.

The product was a mixture of N,N'-didodecylterephthaldiamide;N,N'-diphenylterephthaldiamide; and N-dodecyl-N'-phenylterephthaldiamide, predominating in the latter. pointof 272-298 C. The principal reaction involved was as follows, yieldingN-dodecyl-N'-phenylterephthaldiamide:

Example 2.N,N'-di-p-tolylterephthaldiamide 1284 grams of p-toluidine and582 grams of dimethyl terephthalate (12 and 3 gram mols, respectively)were heated and stirred together at -210 C. for 6 hours. The product waswashed three times with boiling benzene and was dried. A yield of 733grams was obtained con sisting of two-thirds of the ditoluidide andone-third methyl-N-tolylterephthalamate having the following respectiveformulas:-

omo-oo-Q-oo-mz-Q-cm The saponification number of the product was 154 andnitrogen content was 6.54%.

Example 3.- ,N'-di-2-anthraquinoneterephthaldiamide thaldiamide waswashed with hot water until the filtrate was free from chloride ion.4.02% by weight nitrogen.

GREASE PREPARATION Example 4 A mixture of 200 grams of the product ofExample l (a mixture of N,N'-didodecylterephthaldiamide; N,N'-di- Theproduct contained It contained 7.5% nitrogen and had a melting,

Example A mixture of 25 grams of the product of Example 2 6. Example 6150 grams of N,N'-di-2-anthraquinoneterephthaldiamide for Example 3hereinabove and 350 grams of a poly(phenylmethyl siloxane) (i.e., DowCorning DC-550) were heated to 500 F.; then cooled to 350 F.; and

milled through a Manton-Gaulinmill at4000 p.s.i. The resulting greasehad an ASTM dropping point of 580+ F.; a P of 237; a P of 360; and ahigh speed bearing life of 331 hours at 450 F.

Other greases containing a variety. of diamides of terephthalic acid'asthickeners for a variety of oils are illustrated, together with testresults, in the following table:

TABLE ASTM Thickener Percent Base Dropping P P Bearing Thickener OilPfizlt, Stability 20 (1) 375 195 (1)N-octadeey1-N-pheny1terephthaldlamide 30 2) 423 18 E1) 390 20s (2)N-dodecyl-N'-phenyl tererhthaldmmide 25 1) 475 201 19 (1) 475 225 20 (2)543 199 (3) N-tetradecyl-N'-pheny1terephthaldiamlde i8 23? 2 (1) 502 23517 (2) 538 176 4 C H NH-OO'Q-OO-NH-CIh-CIL-NHCO 17 1 33s 238 320 C1ssrNH-CO- a CnHr NH- 0 o-Q- c O-NH--NH (6) CmHnNH-CO- -CO-NH- -NH- CreuNH-C0--CO'NH--NH- 13 (1) 580+ 15 (1) 276 CmHm-NH-CO-QOO- 8 N-methl-N'-to1 ltere hthalamata lus NN'-dltolyl terephthaldi- U nmidn y y p p25 (2 500+ 9 OrHrI-NH-CO-QCO-NH-Ofln (a) an 231 352 (one-thirdmethyl-N-tolylterephthalamate and two-thirdsN,N'-di-p-tolylterephthaldiamide) and 75 grams of a poly-(phenylrnethylsiloxane) oil (Dow Corning DC-550) was heated with stirring to 600 F.;pan cooled; then milled in a needle valve mill at 4000 p.s.i. Theresulting smooth, soft brease had an ASTM dropping point of 500+ F.;worked penetration (P of 348; and a high speed hearing life of 510 hours(average of two runs, 354 and 665 hours) at 450 F. and of 307 hours(average of two runs, 212 and 401 hours) at 500 F. The high speedbearing life test (quoted as Mil-G-25013) was run as follows:

A 204K Conrad type 8-ball bearing packed with grease was operated at10,000 r.p.rn. continuously for 22 hours at the designated temperature.The bearing was then cooled to room temperature during a period of 2hours, then run at 10,000 r.p.m. for another 22 hours. This cycle wasrepeated until the bearing failed.

In the foregoing table, Base Oil No. (1) was a California paraflinicbase oil having a viscosity of 450 SSU at F.; Base Oil N0. (2) was asynthetic oil, Dow Corning DC-550, which is a poly(phenylmethylsiloxane); and Base Oil No. (3) was a California naphthenic base oilhaving a viscosity of 1700 SSU at 100 F.

It will, therefore, be apparent that novel compounds have been providedwhich are nonmetallic and which are capable of functioning as greasethickeners. Greases formed are characterized by high dropping pointsand, in many cases, by exceptionally high dropping points. The lattercharacteristic is highly advantageous in view of the fact that thethickeners are nonmetallic.

I claim:

1. The compound, N-tetradecyl-N'-phenylterephthaldiamide.

2. The compound, N-dodecyl-N'-phenylterephthaldiamide.

3. The compound, N-octadecyl-N'-phenylterephthaldiamide.

2,272,466 Hummel Feb. 10, 1942 OTHER REFERENCES 5 Rosehmund et al.:Deutsche Chemische Gesellschaft;

vol. 54 (1921), p. 2892. Dermer et aL: J. Org. Chem, vol. 8 (1942), pp.168- 4. The compound wherein R is an alkyl and R is a member selectedfrom the group consisting of phenyl and tolyl.

References Cited in the file of this patent eta1 J Amer chem soc vol 68(1946) UNITED STATES PATENTS 10 539440. 2,123,375

Mieg et a1. July 12, 1938 Schumacher et a1. May 23, 1939 UNITED STATESPATENT OFFICE CERTIFICATION OF CURRECTION N00 I 7v Bruce W. Hotten It ish'ereby certified that error appears in the above munbered patentrequiring correction and that the said Letters Patent should read ascorrected below Column 5, line 63, for "brease" read grease column 6,line 3, for "amide for read amlde of Signed and sealed this 22nd day ofAugust 1961.

XSEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents

4. THE COMPOUND